Many waters contain contaminants that can present a hazard to people or the environment, or make further processing, such as evaporation or reverse osmosis more difficult. Membranes are commonly used to remove such contaminants. Membrane elements are typically made of plastics, polymers or ceramics, both of which are frequently placed inside a housing to contain the pressurized fluid to be treated. The element and housing combination are referred to as membrane modules or modules. Such housings also provide separate ports to allow a feed to enter the module, filtrate to exit after being processed through the membrane, and a retentate for removal of the filtered material.
Ceramic membranes are commonly used as a multilayer structure with a relatively high permeability support, and a thinner separation layer which enables the separation by passing some components (typically water and small solutes) while retaining others. In order to increase surface area a number of channels are typically present in the support, each with a coating. In one example of a use of the membrane, feed enters these channels before passing through the membrane into the support structure. In other examples, the coasting is on an outside surface, and feed enters from the outside and flows inward to the channels. To keep feed from passing directly into the support on either end, a face end seal layer is used to prevent transport through the ends. Commonly used materials for face end seals include epoxies, polyurethanes, elastomers, glass or other suitable materials. In comparison to the other components in a ceramic housing this face end seal is particularly sensitive to mechanical damage due to both the material properties of the face end seal, and the fact that housings which have been used to date leave the face end seal at the end of the housing preventing it from serving as shielding. What is needed is a module design allowing the housing to protect, shield, and/or create an impingement zone or buffer space around the face end seal improving the durability and integrity of the membrane.
Further, ceramic membrane modules are typically heavy and require mechanical support. Conventional ceramic housings require the ceramic in the housing to be supported so that the external end caps which are affixed to the bottom of the housing can be installed before use, or removed while in a system to access the ceramic, for instance to determine whether damage to the face end seal has occurred. This requires a method to support the weight of the ceramic above the ground, which makes routine inspections difficult to perform. This can be accomplished by recessing the element inside the housing. However to do so there is a need for a process to provide potting material to seal the element to the housing, while preventing the potting material from flowing over the end of the module and blocking channels. What is needed is a process to position the module within the housing and seal the channel area on the end of the element so that potting material can be applied to mount the element within the housing without blocking channels.